Polyester of fatty acids & sugar-alcohols are partially absorbed by small intestine.Thereby yielding less metabolizable energy than estimated by combustion.To determine rate of absorption & further metabolism, a polyester containing either 14C1-oleic acid will be given to subjects with regular meal.Free 13C1-oleic acid will serve as control.Recovery rates & enrichment of tracer in breath will allow comparison rate of absorption/oxidation of esterified substrate & free substrate Furthermore, analyses of feces/urine will determine amount of substrate that is excreted.